Frequency Analysis of Disturbance Torque Exerted on a Carriage Arm in Hard Disk Drives Using Hilbert–Huang Transform

In this paper, we applied the Hilbert-Huang transform (HHT) to the time series of the torque exerted on the carriage arm of a hard disk drive, which was calculated using the finite-element analysis. Then, a Fourier transform (FT) was implemented to perform frequency analysis; the results were subsequently compared with the HHT results. A comparison of both spectra revealed the superior ability of HHT to perform frequency analysis of flow phenomena via disturbance torque analysis. Furthermore, the HHT results confirmed that to achieve more precise head positioning, it is necessary to decrease torque fluctuations induced by the non-stationary phenomena that are not always observed in the power spectrum obtained via the FT analysis, such as vortex shedding around an arm.